When it genuinely applies
This is the narrowest of the commercial grounds and the one most often claimed without support. Energy efficiency works usually raise commercial value, or at worst leave it flat, so a devaluation argument runs against the grain and needs a specific reason.
The cases where it holds tend to share a feature: the measure alters something the market is buying.
- External wall insulation on a building whose elevation is the asset – a period frontage in a conservation-adjacent retail pitch
- Loss of lettable area – internal wall insulation reducing a small demise below a viable floorplate, or plant taking usable space
- Loss of a feature the market pays for – replacing shopfront glazing, altering a double-height volume, blocking rooflights
- Interference with a specialist use where the fit-out is the value
What the report must do
- Identify the specific measures from the EPC recommendation report
- State market value before, and market value with the measures installed
- Express the reduction as a percentage and cross the 5% threshold explicitly
- Be signed by a RICS Registered Valuer, independent of you
- Be dated, and retained for the life of the exemption plus the six-year enforcement reach
Find the certificate you already have
Search the Energy Performance of Buildings Register for your building. It is free, there is no sign-up, and it takes about ten seconds.
Common questions
Who can provide the devaluation report?
An independent surveyor on the RICS Register of Valuers. It cannot be your own in-house view, and it cannot be the agent selling the building.
Is 5% of the whole building or the works?
Of the market value of the property. The test is whether installing the measures would reduce that value by more than five per cent.